In recent years, a broadcast service including both a high-speed transmission channel and a low-speed transmission channel, the channels having different combinations of error resistance and transmissible video signal quality, has been implemented. A broadcast of the high-speed transmission channel is a broadcast service for a fixed TV, and a broadcast of the low-speed transmission channel is a broadcast service for a mobile TV. In an ISDB-T system adopted in Japan, a full-segment broadcast corresponds to the broadcast service of the high-speed transmission channel and a one-segment broadcast corresponds to the broadcast service of the low-speed transmission channel.
Recently, there has been developed a receiver having a function of automatically switching a demodulation target service between a full-segment broadcast and a one-segment broadcast. It is general to switch the full-segment broadcast and the one-segment broadcast based on a received signal quality value such as a bit-error rate (BER) or the carrier-to-noise power ratio (CN). For example, when the received signal quality value such as the CN exceeds a given reference value associated with the full-segment broadcast, a demodulation target broadcast signal is switched to a full-segment broadcast service.
However, since the full-segment broadcast has the low error resistance, when the switching is performed using the same reference value irrespective of a difference in environment such as a moving state/stationary state of the receiver, inconvenience, for example, repetition of switching between the full-segment broadcast and the one-segment broadcast may possibly occur.